This is an open label, multicenter study designed to provide amprenavir to adults (greater than and equal to 18 years of age) with HIV -1 infection who have evidence of treatment failure in the face of standard therapy, or are intolerant to standard therapy. Informed consent will be obtained at pre-entry. Females of childbearing potential will have a pregnancy test (HCG) at the pre-entry visit (within 14 days of study day 1). Patients will be seen in the clinic at pre-entry, baseline (Day 1) and every 4 weeks thereafter. Pre-entry/baseline information will be collected, including demography data, current antiretroviral treatments, HIV -1 associated conditions and adverse events will be collected at every scheduled visit. Hematology, serum chemistry, plasma HIV-1 viral load determination and CD4+ cell count measurements will be collected at pre-entry and every 12 weeks thereafter, in accordance with the standard of care. Since optimal therapy usually included the combined use of 2 or more antiretroviral agents in subjects who are failing current antiretroviral therapy, amprenavir must be initiated as a component of treatment regime that also included at least one other antiretroviral drug that the subject has not previously received. To accommodate this recommendation, the use of therapies that are accessed via- open-label programs will be allowed upon approval of both Glaxo-Wellcome and the other sponsor(s). Limited drug interaction data are available for amprenavir; therefore caution should be used in selecting agents for combination therapy.